Music: A Mathematical Offering (2008)
homepages.abdn.ac.uk
homepages.abdn.ac.uk
If you prefer to have an actual book, it is directly available for purchase on Amazon: http://www.amazon.com/Music-Mathematical-Offering-Dave-Benso...
The SOS Synth secrets covers some of this material as well: http://www.soundonsound.com/sos/may00/articles/synth.htm
SOS index: http://www.soundonsound.com/sos/allsynthsecrets.htm